Which of the following is a potential threat to the validity of a free speech sample as a measure of the child's speech accuracy when compared to a standardized picture naming procedure?

• A. The free speech sample procedure lacks ecological validity because it is not standardized
• B. The child may become tired and not present her best performance because it can take so long to obtain 100 unique words
• C. The sample of speech sounds obtained may not be representative of the phonology of the language
• D. Most children with speech difficulties will not talk to the SLP because they are embarrassed by their speech errors

Answer: (C)

Understanding validity here means how well the free speech sample actually reflects the child’s true phonology across the language. A standardized picture naming task is designed to elicit a broad, controlled range of sounds and contexts, providing a consistent benchmark for measuring accuracy. A free speech sample, while natural, may not include all phonemes or contexts, so the sounds collected might not represent the full phonological system. If certain sounds never occur in the spontaneous sample, your assessment could misrepresent the child’s overall phonology when compared to the standardized procedure. The other concerns—tiredness from long recording, embarrassment reducing participation, or ecological aspects—affect data quality or participation more than the fundamental representativeness of phonology captured.